What DIDN'T cause the boom

The National Weather Service reports that "the PDX Boom was not weather related".

Western Air Defense (part of NORAD) claims the boom was not aircraft related.

PGE shows no power outages related to the Boom, so rule out the power grid.

And we all know it wasn't a fucking pipe bomb.

What REALLY caused the Boom?

A meth lab blowing up

With the Portland meth problem, it makes sense that there would be a lot of meth labs in our city. Meth labs are really only good for two things: making meth and exploding.

Perhaps one blew up and the owner was able to put out the fire without alerting the authorities.

Protesting related to the police shooting of Aaron Campbell

On January 29th, Aaron Campbell was shot in the back by Portland PD when emerging from an apartment with his hands above his head. Last week a grand jury found the shooter not guilty, which led to public outrage among everyone from civil rights leaders to militant anarchist groups.

The angrier of these groups staged a "black bloc" the day after the Portland Boom, but someone might have gotten started a bit early.

It seems that the local government might cover up any actions of these groups, especially if they couldn't find a suspect (or scape goat). If they announced that the loud noise was caused by the militant actions of these groups, then it might cause the next days "black bloc" to be more successful both in recruiting new members and inciting panic.

A sonic boom

Another thought is that it was a sonic boom. However sonic booms can only be acheived by breaking the speed of sound, which is against federal air traffic control regulations.

But that doesn't mean that it can't be done illegally. Also, the military might be testing a top-secret supersonic jet over our fair city.

Unexplained phenomena

Now I don't want to come right out and say it was caused by "little green men", but perhaps the Boom was caused by phenomena that we don't yet understand scientifically (whether natural or unnatural).

They might just not know

It might simply be that the local Portland government simply doesn't know what caused the boom. Fire crews were dispatched throughout SE Portland, finding nothing even hours after the Boom.

So maybe they made up the pipe-bomb story to avoid panic and to preserve the illusion that they're in control.

Other Loud Booms

March 18, 2010 - Maysville, Kentucky

A large unexplained boom with possible tremors was heard the night of March 18 in Maysville, KY, and all the way into Ohio.